1. Field of the Invention
This invention relates broadly to surgical instruments and methods of their use. More particularly, this invention relates to a minimally invasive surgical assembly that incorporates both a needle and a cauterizing device that is extendible through and beyond the needle and retractable into the needle. The invention has particular application to laparoscopic-type surgery, although it is not limited thereto.
2. State of the Art
Over the last two decades, minimally invasive surgery has become the standard for many types of surgeries which were previously accomplished through open surgery. Minimally invasive surgery generally involves introducing an optical element (e.g., laparoscope or endoscope) through a surgical or natural port in the body, advancing one or more surgical instruments through additional ports or through the endoscope, conducting the surgery with the surgical instruments, and withdrawing the instruments and scope from the body. In laparoscopic surgery (broadly defined herein to be any surgery where a port is made via a surgical incision, including but not limited to abdominal laparoscopy, arthroscopy, spinal laparoscopy, etc.), a port for a scope is typically made using a surgical trocar assembly. The trocar assembly often includes a port, a sharp pointed element (trocar) extending through and beyond the distal end of the port, and at least in the case of abdominal laparoscopy, a valve on the proximal portion of the port. Typically, a small incision is made in the skin at a desired location in the patient. The trocar assembly, with the trocar extending out of the port, is then forced through the incision, thereby widening the incision and permitting the port to extend through the incision, past any facie, and into the body (cavity). The trocar is then withdrawn, leaving the port in place. In certain circumstances, an insufflation element may be attached to the trocar port in order to insufflate the surgical site. An optical element may then be introduced through the trocar port. Additional ports are then typically made so that additional laparoscopic instruments may be introduced into the body.
Trocar assemblies are manufactured in different sizes. Typical trocar port sizes include 5 mm, 10 mm and 12 mm (available from companies such as Taut and U.S. Surgical), which are sized to permit variously sized laparoscopic instruments to be introduced therethrough including, e.g., graspers, dissectors, staplers, scissors, suction/irrigators, clamps, forceps, biopsy forceps, etc. Laparoscopic surgery has reduced the trauma associated with various surgical procedures and has concomitantly reduced recovery time from these surgeries. The 5 mm trocar ports from the various instruments used in laparoscopic surgery leave a plurality of holes that must be stitched, which typically result in scars.
One surgical instrument often used during laparoscopic surgery is a cauterization tool. Cauterization (cautery) tools are employed for stopping internal bleeding by cauterizing areas inside the body that have been pierced or opened during surgery, and for cutting through tissue inside of the body in order to destroy and/or remove it. The cautery tool is typically electrified to destroy the tissue. The cautery device may be electrified at different voltages to achieve different functions. At lower voltages, continuous alternating current quickly produces heat that vaporizes tissue at the tip of the cautery tool. At higher voltages, heat is produced more slowly, which causes more widespread tissue damage near the tip of the cautery tool. The latter effect causes blood near the site to coagulate. The process of using electricity to destroy tissue is called “electrocauterization.”
Electrocauterization is performed in either a monopolar or bipolar mode. In monopolar electrocauterization, a patient's body serves as the ground, and current passes from the cautery device to the patient. In bipolar electrocauterization, the cautery device contains sending and receiving electrodes that are placed around tissue. The current passes between the electrodes and cauterizes the tissue therebetween.
A common cautery device used in monopolar electrocauterization is a scalpel-shaped spatula, which may serve as both a coagulator and an electric scalpel. A surgeon operates the cautery device by pushing a button on its shaft and/or by depressing a foot pedal, thereby allowing current to flow through the cautery device.
A number of cautery and needle combinations are known in the art. U.S. Pat. No. 5,578,030 discloses a biopsy needle that procures a tissue specimen and cauterizes the resulting wound, which minimizes bleeding and helps prevent the proliferation of cancer cells along the path of the needle. The device has a sharp cutting edge disposed at a junction between a front wall and a top surface, a configuration that enables tissue to be cut and forced into the biopsy needle as the biopsy needle is retracted from a patient. A conductor applies electrical current to the needle, which heats it and cauterizes the wound resulting from the excision of the tissue specimen.
U.S. Pat. No. 5,342,357 discloses an electrosurgical probe that cuts and cauterizes tissue. The device is adapted to accommodate fluid flow through an outlet port to surrounding tissue so as to limit heat transfer from the device thereto, thereby preventing the surrounding tissue from sticking to the device.
U.S. Pat. No. 5,906,620 discloses a surgical instrument assembly that includes a cauterization snare and a suture member, both of which are disposed in a first tubular sheath. The suture member is also disposed in a second tubular sheath that facilitates the release and positioning of the suture member around a selected body of tissue. The second tubular sheath is movably disposed in the first tubular sheath and contains a tensioning means extending through the second tubular sheath for tightening the suture member. The device is used to remove a polyp or other body tissue.